Recursively processes a directory of templates, generating a set of result files in the same directory or in a parallel directory. Each file in the source directory may be template-processed, copied, or ignored depending on its pathname.

A code reference that takes the full template filename and the Any::Template::ProcessDir object as arguments, and returns the result string. This can use Any::Template or another method altogether. By default it calls "process_text" on the contents of the file.